scholarly journals Thermoelectric Properties of ZnSb Films Grown by MOCVD

1997 ◽  
Vol 478 ◽  
Author(s):  
R. Venkatasubramanian ◽  
E. Watko ◽  
T. Colpitts
Keyword(s):  
Thermoelectric Properties ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Free Carrier ◽  
Conductivity Measurements ◽  
Seebeck Coefficients ◽  
Short Annealing ◽  
P Type ◽  
Concentration Levels

AbstractThe thermoelectric properties of ZnSb films grown by metallorganic chemical vapor deposition (MOCVD) are reported. The growth conditions necessary to obtain stoichiometric ZnSb films and the effects of various growth parameters on the electrical conductivity and Seebeck coefficients of the films are described. The as-grown ZnSb films are p-type. It was observed that the thicker ZnSb films offer improved carrier mobilities and lower free-carrier concentration levels. The Seebeck coefficient of ZnSb films was found to rise rapidly at approximately 160°C. The thicker films, due to the lower doping levels, indicate higher Seebeck coefficients between 25 to 200°C. A short annealing of the ZnSb film at temperatures of ˜ 200°C results in reduced free-carrier level. Thermal conductivity measurements of ZnSb films using the 3-ω method are also presented.

Study on Phases and Thermoelectric Properties of Bulk Fe4Sb12 and Fe3CoSb12 Prepared by Milling and Sintering

2011 ◽  
Vol 121-126 ◽  
pp. 1526-1529
Author(s):  
Ke Gao Liu ◽  
Jing Li
Keyword(s):  
Thermoelectric Properties ◽  
Impurity Phase ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Type Semiconductor ◽  
P Type

Bulk Fe4Sb12 and Fe3CoSb12 were prepared by sintering at 600 °C. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk samples are skutterudite with impurity phase FeSb2. The electric resistivities of the samples increase with temperature rising at 100~500 °C. The bulk samples are P-type semiconductor materials. The Seebeck coefficients of the bulk Fe4Sb12 are higher than those of bulk Fe3CoSb12 samples at 100~200 °C but lower at 300~500 °C. The power factor of the bulk Fe4Sb12 samples decreases with temperature rising while that of bulk Fe3CoSb12 samples increases with temperature rising at 100~500 °C. The thermal conductivities of the bulk Fe4Sb12 samples are relatively higher than those of and Fe3CoSb12, which maximum value is up to 0.0974 Wm-1K-1. The ZT value of bulk Fe3CoSb12 increases with temperature rising at 100~500 °C, the maximum value is up to 0.031.The ZT values of the bulk Fe4Sb12 samples are higher than those of bulk Fe3CoSb12 at 100~300 °C while lower at 400~500 °C.

scholarly journals Phosphorous Doping of Microcrystalline CVD Diamond Using Modified Conditions

2007 ◽  
Vol 1039 ◽  
Author(s):  
Ken Haenen ◽  
Andrada Lazea ◽  
Vincent Mortet ◽  
Jan D'Haen ◽  
Peter Geithner ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Growth Conditions ◽  
Diamond Surfaces ◽  
Cvd Growth ◽  
Oriented Polycrystalline ◽  
Electron Back Scattered Diffraction

AbstractPhosphorous-doping of predominantly (110) oriented polycrystalline CVD diamond films is presented. Incorporation of phosphorous into the diamond grains was accomplished by using novel microwave plasma enhanced chemical vapor deposition (MW PE CVD) growth conditions. The substitutional nature of the phosphorous atom was confirmed by applying the quasi-steady-state photocurrent technique (PC) and cathodoluminescence (CL) measurements at low temperature. Topographical information and the relation between substrate and P-doped film grain orientation was obtained with scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). The optimized growth parameters for P-doped layers on (110) oriented polycrystalline diamond differ substantially from the standard conditions reported in literature for P-doping of single crystalline (111) and (100) oriented diamond surfaces.

Thermoelectric Properties of Co1-xNbxSb3 Prepared by Induction Melting

2005 ◽  
Vol 486-487 ◽  
pp. 602-605 ◽  
Author(s):  
J.B. Park ◽  
S.-W. You ◽  
K.W. Cho ◽  
J.I. Lee ◽  
Soon Chul Ur ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Thermoelectric Properties ◽  
Induction Melting ◽  
Thermoelectric Power Factor ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
High Temperature Maximum ◽  
Higher Temperature ◽  
Nb Doping ◽  
P Type

Induction melting was attempted to prepare the undoped and Nb-doped CoSb3 compounds, and their thermoelectric properties were investigated. Single phase d-CoSb3 was successfully obtained by induction melting and subsequent annealing at 400°C for 2 hours in vacuum. The positive signs of Seebeck coefficients for all the specimens revealed that Nb atoms acted as p-type dopants by substituting Co atoms. Electrical conductivity decreased and then increased withincreasing temperature, indicating mixed behaviors of metallic and semiconducting conductions. Electrical conductivity increased by Nb doping, and it was saturated at high temperature. Maximum value of the thermoelectric power factor was shifted to higher temperature with the increasing amount of Nb doping, mainly originated from the Seebeck coefficient variation.

Investigation of Wide Bandgap Semiconductors for Thermoelectric Applications

2013 ◽  
Vol 1490 ◽  
pp. 161-166 ◽  
Author(s):  
B. Kucukgok ◽  
Q. He ◽  
A. Carlson ◽  
A. G. Melton ◽  
I. T. Ferguson ◽  
...  
Keyword(s):  
Power Generation ◽  
High Temperatures ◽  
Thermoelectric Properties ◽  
Chemical Properties ◽  
Chemical Vapor ◽  
Wide Bandgap ◽  
Organic Chemical ◽  
Seebeck Coefficients ◽  
Wide Bandgap Materials ◽  
Bandgap Semiconductors

ABSTRACTThermoelectric materials with stable mechanical and chemical properties at high temperature are required for power generation applications. For example, gas temperatures up to 1000°C are normally present in the waste stream of industrial processes and this can be used for electricity generation. There are few semiconductor materials that can operate effectively at these high temperatures. One solution may be the use of wide bandgap materials, and in particular GaN-based materials, which may offer a traditional semiconductor solution for high temperatures thermoelectric power generation. In particular, the ability to both grow GaN-based materials and fabricate them into devices is well understood if their thermoelectric properties are favorable. To investigate the possibility of using III-Nitride and its alloys for thermoelectric applications, we synthesized and characterized room temperature thermoelectric properties of metal organic chemical vapor deposition grown GaN and InGaN with different carrier concentrations and indium compositions. The promising value of Seebeck coefficients and power factors of Si-doped GaN and InGaN indicated that these materials are suitable for thermoelectric applications.

Study on Phases and Thermoelectric Properties of Bulk FexCo4-xSb12 Sintered by MM-SPS

2011 ◽  
Vol 179-180 ◽  
pp. 294-297
Author(s):  
Ke Gao Liu ◽  
Shi Lei
Keyword(s):  
Thermoelectric Properties ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
Semiconducting Materials ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Plasma Sintering ◽  
Electrical Resistivities ◽  
Spark Plasma ◽  
P Type

Bulk FexCo4-xSb12 with x varies from 0.1 to 2.0 were prepared by mechanical milling (MM) and spark plasma sintering (SPS). The phases of the products were characterized by X-ray diffraction (XRD) and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk FexCo4-xSb12 are skutterudite. The electrical resistivities of the products increase first and then decrease. The Seebeck coefficients ( ) are negative when x=0.1 at 100 °C and 200 °C while positive at 300~500 °C. The products with x=0.5~2.0 at 100~500 °C are P type semiconducting materials due to their positive values. The thermal conductivities of most samples increase first and then decrease with x increasing and the maximum is up to 0.39 Wm-1K-1 when x=1.0. The ZT values at 200~500 °C increase first and then decrease with x increasing when x=0.1~1.0 and x=1.0~2.0 respectively and the maximum ZT value is 0.196 when x=1.5 at 400 °C.

First-principles study of the structural and thermoelectric properties of Y-doped α-SrSi2

2022 ◽  
Author(s):  
Masato Yamaguchi ◽  
Daishi Shiojiri ◽  
Tsutomu Iida ◽  
Naomi Hirayama ◽  
Yoji IMAI
Keyword(s):  
Thermoelectric Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Narrow Band ◽  
Hybrid Functional ◽  
Promising Candidate ◽  
Functional Theory ◽  
Seebeck Coefficients ◽  
Increasing Temperature ◽  
P Type

Abstract The narrow-gap semiconductor α-SrSi2 is a promising candidate for low-temperature thermoelectric applications with low environmental load. The only experimental report in which α-SrSi2 is reported to have n-type conductivity is one where it had been doped with yttrium. To further clarify the effects of impurities, theoretical studies are needed. The α-SrSi2 has a very narrow band gap (~13–35 meV), causing difficulties in the accurate calculation of the electronic and thermoelectric properties. In our previous study, we overcame this problem for undoped α-SrSi2 using hybrid functional theory. We used this method in this study to investigate the structures, energetic stabilities, electronic structures, and thermoelectric properties of Y-doped α-SrSi2. The results indicate that substitution at Sr-sites is energetically about two times more stable than that at Si-sites. Furthermore, negative Seebeck coefficients were obtained at low temperatures and reverted to p-type with increasing temperature, which is consistent with the experimental results.

Aluminium Doping of 4H-SiC Grown with HexaMethylDiSilane

2005 ◽  
Vol 483-485 ◽  
pp. 121-124 ◽  
Author(s):  
C. Sartel ◽  
Véronique Soulière ◽  
Marcin Zielinski ◽  
Yves Monteil ◽  
Jean Camassel ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Parameters ◽  
Growth Conditions ◽  
P Systems ◽  
P System ◽  
Aluminium Concentration ◽  
P Type ◽  
Non Destructive ◽  
Aluminium Doping

We report on the study of the p-type doping of 4H-SiC material using HexaMethylDiSilane/TriMethylAluminium/Propane (HMDS/TMA/P) system in place of the usual Silane/TriMethylAluminium/Propane (S/TMA/P) precursors. The influence of growth parameters such as TMA flow, growth rate or C/Si ratio is investigated. The aluminium incorporation level is deduced from both by C(V) (mercury probe) and SIMS measurements. The presence of aluminium in the layers is confirmed by non-destructive optical micro-Raman experiments. Good quality p-type, aluminium doped 4H-SiC layers can be grown using HMDS/TMA/P system. The amount of aluminium in the layers can be controlled by choosing the growth conditions and an aluminium concentration as high as 2x1019 at.cm-3 has been reached.Finally, comparing the two HMDS/TMA/P and S/TMA/P systems, no difference in aluminium incorporation has been found.

Thermoelectric Properties of Co1-xNbxSb3 Prepared by Induction Melting

2005 ◽  
Vol 486-487 ◽  
pp. 554-557
Author(s):  
J.B. Park ◽  
S.-W. You ◽  
K.W. Cho ◽  
J.I. Lee ◽  
Soon Chul Ur ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Thermoelectric Properties ◽  
Induction Melting ◽  
Thermoelectric Power Factor ◽  
Seebeck Coefficients ◽  
High Temperature Maximum ◽  
Higher Temperature ◽  
Nb Doping ◽  
Increasing Temperature ◽  
P Type

Induction melting was attempted to prepare the undoped and Nb-doped CoSb3 compounds, and their thermoelectric properties were investigated. Single phase d-CoSb3 was successfully obtained by induction melting and subsequent annealing at 400°C for 2 hours in vacuum. The positive signs of Seebeck coefficients for all the specimens revealed that Nb atoms acted as p-type dopants by substituting Co atoms. Electrical conductivity decreased and then increased with increasing temperature, indicating mixed behaviors of metallic and semiconducting conductions. Electrical conductivity increased by Nb doping, and it was saturated at high temperature. Maximum value of the thermoelectric power factor was shifted to higher temperature with the increasing amount of Nb doping, mainly originated from the Seebeck coefficient variation.

Thermoelectric Properties of Electrodeposited BiSbTe Nanowires

2010 ◽  
Vol 1267 ◽  
Author(s):  
Raja Sekharam Mannam ◽  
Despina Davis
Keyword(s):  
Nitric Acid ◽  
Thermoelectric Properties ◽  
Composition Analysis ◽  
Antimony Telluride ◽  
Bismuth Antimony Telluride ◽  
Seebeck Coefficients ◽  
Bismuth Antimony ◽  
P Type

AbstractBismuth antimony telluride (BiSbTe) nanowires were electrodeposited at constant potentials into polycarbonate templates from a tartaric-nitric acid baths having different electrolyte compositions. Composition analysis of the nanowires showed that Sb deposits at higher potentials compared to BiTe. Maximum seebeck coefficients of -337.7 μV/K and 227.2 μV/K were obtained for n-type and p-type nanowires samples Bi4.6Te5.4 and Bi4.3Sb5 respectively. Nonmonotonic resistance behavior was observed for all the nanowires.

Metal Organic Chemical Vapor Deposition of Zinc Oxide

2005 ◽  
Vol 892 ◽  
Author(s):  
William E. Fenwick ◽  
Vincent T. Woods ◽  
Ming Pan ◽  
Nola Li ◽  
Matthew H. Kane ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

AbstractThin films of ZnO were grown by metal organic chemical vapor deposition (MOCVD) in a vertical injection rotating disk reactor (RDR) system on sapphire substrates. Kinetics of ZnO growth by MOCVD were studied and an optimal growth window for a RDR tool was determined. Experimental growth conditions were chosen based on calculations of Reynolds Number (Re) and mixed convection parameter in order to select a growth window with stable gas flow and uniform heat transfer. Growth parameters were systemically varied within this window to determine the optimal growth conditions for this MOCVD tool and to study how these parameters affect film growth and quality. Properties of ZnNiO films grown by MOCVD were also studied to determine the effects of Ni incorporation on structural, optical, and magnetic properties.

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